Schistosomiasis Flashcards
infective larval stage
metacercariae
Sequence of infection and transmission
interval from cercarial penetration to sexual maturation and egg production
Prepatent period
only stage of the parasite’s life cycle that can be detected in humans
schistosome egg
Pathogenesis of chronic schistosomiasis
late chronic-stage infections are characterized by accumulation of dead calcified eggs in tissue
severe periportal fibrosis caused by egg-induced granulomatous responses
Symmers clay pipestem fibrosis
disease manifestations of intestinal schistosomiasis
associated with parasite eggs passing through or becoming trapped in intestinal tissue
-microulcerations, superficial bleeding, pseudopolyposis
disease manifestations of S. hematobium
- Active stage
- children, adolescents, younger adults,
- egg excretion in urine, proteinuria, microscopic or macroscopic hematuria
-painless terminal hematuria - Chronic stage
- older individuals
- sparse or no urinary egg excretion despite urogenital tract pathoogy
characteristic sign of active stage of S. hematobium
painless terminal hematuria
caused by schistosome eggs in liver tissue and occurs in S. mansoni and S. japonicum
Hepatosplenic schistosomiasis
standard diagnostic method
detection of schistosome eggs in stool
drug of choice for the treatment of schistosomiasis
Praziquantel
Treatment regimen of schistosomiasis
**in patients not cured by initial treatment, the same dose can be repeated at weekly intervals for 2 weeks
- may be necessary to repeat the dose 6-12 weeks later, esp if eosinophilia or symptoms persist despite treatment
treatment for Cercarial dermatitis (Swimmer’s itch)
no treatment
reduce symptoms: antihistamines, topical antihistamines or glucocorticoids
a maculopapular rash that can develop in people who have no previously been exposed to schistosomiasis
Cercarial dermatitis
